Signs of a Bad Clutch
Nearly every type of vehicle with a combustible engine requires a clutch to change gears, which helps to convert power into speed. The clutch is a mechanical connection between the engine and the transmission. When the clutch is disengaged from the clutch plate, the vehicle can smoothly transition to a lower or higher gear. In a heavy-duty truck or classic sports car with manual transmission, the driver operates the clutch pedal to the far left of the brake pedal. In vehicles with automatic transmissions, the clutches are engaged by pressurized fluid and springs inside the transmission housing.
Signs of a bad clutch include the engine revving higher than normal when you try to get up to speed. Essentially, stepping on the gas pedal causes a large amount of power from the engine, but little actual acceleration. This mechanical failure is often referred to as gear slippage, which can release a strong burning smell. A 'spongy clutch' that does not have consistent firm pressure is a sign that there is air in the clutch hydraulic line. Some broken manual clutches are so loose that the pedal hits the floorboard, while a hard clutch is one that is so stiff it will not disengage the clutch plate.
The three main components of an automotive clutch are the clutch plate (or clutch disc), the pressure plate and the flywheel. The clutch plate and clutch springs used to operate the pressure plate wear out over time. In comparison, the flywheel is thickly fabricated so you can machine it to remove unwanted grooves and defects. However, deep gouges, cracks and severe heat damage require a complete flywheel replacement. If you are suffering from a worn-out clutch, NAPAOnline has all the aftermarket clutch parts you need.
Friction Builds Under Pressure
Friction clutches, like the ones found in this automatic transmission overhaul kit, create friction between the flywheel on the engine and the clutch plate on the transmission. That generated force rotates the wheels to move the vehicle. Most standard vehicles operate with dry clutches, which are available as a clutch set that includes the clutch disc, pressure plate, slave cylinder and cover assembly. The NAPA Clutch Set for a Diaphragm Spring Pressure Plate includes a release bearing and comes with a 12-Month or 12,000-Mile Warranty. Keep in mind, popular motorcycles and ATVs utilize wet clutches that typically have multiple clutch plates bathed in engine oil.
The force applied to the clutch plate in everyday, commuter driving demands that this transmission part is constructed from durable materials. New, state-of-the-art friction materials are engineered in the automotive aftermarket continually. Hybrid clutches use one material type on one side and a different material on the other to create a blend of both characteristics. One tip is to pay special attention to the grade listed on the part; for a strong grab, go for a high friction coefficient.
Organic clutch plates are comprised of metal woven with fiberglass or carbon fiber. While organic clutches are susceptible to overheating, they provide the softest friction of all possible materials, which means a firm hold, smooth engagement and low chatter (pulsating sensation).
Ceramic clutch plates offer even more holding power than organic material and come with an extremely high heat tolerance. Yet, they are fabricated from hardened material and wear out quickly, especially in commuter vehicles that make frequent stops. This makes ceramic clutch plates best for heavy-duty vehicles.
Whatever you drive, the NAPA Network offers a wide range of transmission clutch replacement parts. Even shop NAPAOnline for centrifugal clutches for popular lawn mowers and power equipment, not to confuse with compressor clutches needed to power most automotive A/C systems.
Our NAPA Experts are Clutch Hitters
Beyond all the metal plates and bearings, there are also a lot of clutch cables and clutch hoses required in a fully operable transmission. These cables can tear, snag on another part or stretch out of alignment, requiring routine maintenance and adjustment over time.
Most modern transmissions rely on hydraulic power to shift gears. The master cylinder of a hydraulic clutch should never run out of fluid, so make sure you know where to locate the clutch fluid reservoir under your hood. If the fluid is cloudy or brown, or if the fluid is low, a technician must 'bleed the clutch' to get out any air bubbles. Then, a professional mechanic should investigate where the contamination is entering or where the fluid is leaking. Schedule an appointment at a local NAPA AutoCare Center near you today if in need of clutch repair.
Most clutches are designed to last approximately 60,000 miles before needing replaced. But there is no guarantee on the lifetime of a clutch pedal pad or clutch brake assembly. If you are looking to replace key components to rebuild a transmission, then checkout NAPA's full catalog of clutch kits and clutch assembly parts for sale.